[Elimination of alkyl phosphates by means of haemoperfusion: experimental results and findings from human casuistics (author's transl)].

We examined the possibility that haemoperfusion with coated activated charcoal might be used in the therapy of alkyl phosphate intoxications. The criterion used was the effect of haemoperfusion on the elimination of alkyl phosphates from the blood. Clearance values for haemoperfusion of nitrostigmine, demeton-S-methyl sulfoxide and dimethoate were determined in vitro. Very good clearance values were ascertained at a blood flow rate of 100ml/min (mitrostigmine 59.20ml/min, demeton-S-methyl sulfoxide 83.70 ml/min, dimethoate 87.84 ml/min). Measurements of the nitrostigmine clearance as a function of various nitrostigmine concentrations in plasma showed that haemoperfusion is effective over a concentration range covering two powers of ten. A 7-h haemoperfusion with coated activated charcoal was performed on a suicide patient with severe nitrostigmine intoxication (Folidol-öl). Clearance values were obtained which were to be expected on the basis of the in vitro investigations. The nitrostigmine concentrations in the extracorporeal blood plasma fell as a result of haemoperfusion to a mid-value of 55 per cent of the initial level. In the patient the level of nitrostigmine in the blood rose showing that there had been a redistribution of nitrostigmine from the tissue or a subsequent absorption from the gastrointestinal tract into the vessels. The results support the use of haemoperfusion with coated activated charcoal in very severe cases of alkyl phosphate intoxication or where standard therapy fails.